Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on linus/master v5.10]
[cannot apply to next-20201217]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/Control-VQ-support-in-vDPA/20201216-150025
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: x86_64-randconfig-a014-20201217 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project cee1e7d14f4628d6174b33640d502bff3b54ae45)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/157796e1c075942914d2096899f4a9b7cf824373
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jason-Wang/Control-VQ-support-in-vDPA/20201216-150025
        git checkout 157796e1c075942914d2096899f4a9b7cf824373
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/vdpa/vdpa_sim/vdpa_sim.c:204:21: warning: no previous prototype for function 'vdpasim_handle_ctrl_mac' [-Wmissing-prototypes]
   virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
                       ^
   drivers/vdpa/vdpa_sim/vdpa_sim.c:204:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
   ^
   static 
>> drivers/vdpa/vdpa_sim/vdpa_sim.c:731:5: warning: no previous prototype for function 'vdpasim_set_group_asid' [-Wmissing-prototypes]
   int vdpasim_set_group_asid(struct vdpa_device *vdpa, unsigned int group,
       ^
   drivers/vdpa/vdpa_sim/vdpa_sim.c:731:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int vdpasim_set_group_asid(struct vdpa_device *vdpa, unsigned int group,
   ^
   static 
   drivers/vdpa/vdpa_sim/vdpa_sim.c:101:19: warning: unused function 'vdpasim16_to_cpu' [-Wunused-function]
   static inline u16 vdpasim16_to_cpu(struct vdpasim *vdpasim, __virtio16 val)
                     ^
   3 warnings generated.


vim +/vdpasim_handle_ctrl_mac +204 drivers/vdpa/vdpa_sim/vdpa_sim.c

   203	
 > 204	virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
   205						    u8 cmd)
   206	{
   207		struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
   208		virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
   209		size_t read;
   210	
   211		switch (cmd) {
   212		case VIRTIO_NET_CTRL_MAC_ADDR_SET:
   213			read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov,
   214						     (void *)vdpasim->config.mac,
   215						     ETH_ALEN);
   216			if (read == ETH_ALEN)
   217				status = VIRTIO_NET_OK;
   218			break;
   219		default:
   220			break;
   221		}
   222	
   223		return status;
   224	}
   225	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org